In industrial fish production in basins, pools or marine fish farms with basins formed by nets, the need arises on certain occasions to handle the fish separately, e.g. in connection with vaccination of fish or by sorting according to size or sex.
The apparatus according to the invention will be explained in connection with the vaccination of fish, but it may also be used in the sorting of fish or fish fry, also simultaneously with a vaccination of the fish.
Today fish or fish fry are vaccinated in two ways. The fish may be vaccinated separately by an automatic manual vaccination apparatus, but this is a physically taxing job as the fish at the same time must be held manually and vaccinated in a certain spot. During this operation the gills or scales of the fish may easily be damaged if the fish is held too tightly, or the vaccination may be effected imprecisely. Fish or fish fry may also be vaccinated in a basin by dosing the vaccine directly into the water, but this method results in a great inaccuracy concerning how large a dose the individual fish receives. Furthermore, the drainage water will be polluted by surplus vaccine.